Authorities have been investigating the possibility that Corwin was having an affair with Lee, who is married and was her neighbor, according to a police search warrant. Authorities have also considered the possibility that Corwin was pregnant with his child.

San Bernardino County Sheriff/AP Photo

This undated photo released by the San Bernardino County, Calif., Sheriff's Department shows Christopher Brandon Lee after an arrest in another investigation.

On June 28, Corwin had told her husband that she was going to be at Joshua Tree National Park, 10 miles away from their home, for the same amount of time that Lee was scheduled to be hunting in the same park. He previously told investigators that he did not see Corwin on the day she disappeared.

The pregnant woman's car was found abandoned a few minutes' drive from Twentynine Palms, the neighborhood where both Lee and Corwin lived, and police said that they saw a single set of footprints going from her abandoned vehicle to a set of tire marks that were consistent with the tires of Lee's Jeep Cherokee.